Ion exchange resin combination



Patented Feb. 26, 1952 ION EXCHANGE nesm communion Grace Rose Stroh, Schenectady, N. Y., assignor to American Cyanamid Company, New York, N. 1 a corporation of Maine NoDl-awing. ApplicationJnne 2, 1947. Serial N0. 751,971

This invention relates to ion exchange materials and more particularly, to stable combinations of cation and anion exchange materials;

Ion exchange as a method by which ionizable solids may be removed from liquid media is known. Among the first developments in the field was the use of a single bed of a cation active zeolite to soften water by replacing the metallic ions lending hardness thereto with sodium ions. It was later found expedient to use two beds of ion active material, one cation active and one anion active, in series and thus remove both cations and anions from liquid media. A most eflective and eflicient demineralization process has as one of its important features the use of -a plurality of pairs of cation and anion exchangers.

The use of a single bed of mixed cation and anion exchange materials in place of separate alternate beds thereof has also been described. Many advantages may be attained by the use of mixed cation and anion exchange materials. In the first place, such a mixture often gives more efficient and more complete demineralization. Secondly, it permits the use of conventional types of equipment for liquid demineralization since it does not require any special equipment. As a result, mixed resins are useful in commercial installations either in the form of beds or as filter coatings and either in batch processes or in continuous processes.

Development in the field of liquid treatment by ion exchange processes has proceeded along another line simultaneously with that of the increased use of mixed ion exchange materials; Since purification of water or, in general, removal of ionizable solids from liquid media by means of a multi-bed system involves the use of heavy equipment including metallic, porcelain, or wooden tanks of considerable size, and because of the heavy demand for a highly purified water of a quality comparable to distilled water in many 3 Claims. (Cl. 260-43) mixed resins whether they be part of a commercial installation or in a portable, disposable cartridge of one sort or another lies in the excessive waste of material originally considered necessarily inherent in processes using mixtures.

Apparently upon combining the two types of ma- 4 terials a sort of neutralization of the eflect of one by the other occurs since the capacity for the removal of ions from liquid media drops considerably in most cases after only a short time of con- A tact.

It' is an object of the present invention to provide a combinationof anion and cation exchange materials which is stable over a period of time.

Another object of the present invention is to provide a stable combination of anion and cation exchange materials which has a shelf life of at least 24 weeks.

The above and other objects are attained by providing for liquid purification by ion exchange a combination of an anion active resin which is the reaction product of an alpha-chloro-beta,- gamma-epoxy compound and at least one alkylene polymine in the ratio of at least two mols of epoxy compound per mole of polyamine with a cation active resin which is a nuclear sulfonated phenol-aldehyde condensation product.

The invention will be described in greater detail in conjunction with the following specific places where stills are not available or where it examples which are merely illustrative and not I intended to be restrictive of the scope of the invention.

' Example 1 A series of cylindrical containers about 16 inches long and about 3 inches in diameter which are made of cardboard lined with metal foil and coated with asphaltum or other waterproofing material are provided with a liquid inlet at the bottom of the container and a liquid outlet at the top of the container. These may consist simply of a cork through which extends a glass tube onto which is attached rubber tubing.

tivated and rinsed granular cation active resin which is a nuclear sulfonated phenol-aldehyde condensation product, and an activated and rinsed anion resin "A" prepared as described in detail below, said mixtures containing the cation and anion resins in a 1 1 proportion by volume. In order to determine the initial capacity of the particular mixture a single cartridge is exhausted by water containing 125 p. p. in. (parts per million) solids as calcium carbonate. The resin mixture is found from the following data to have an initial capacity of 17.8 kilograins as calcium carbonate percubic foot of cation resin.

Properties of Eflluent Specific t roug at n FMA as in as CO: as or ohms ness as p11 p. p. m. p. p.111. p. p. m. p p HL 1 Free mineral acidity.

The remaining cartridges are exhausted in a similar manner. one at a time, at regular intervals. After 28 weeks the final cartridge. upon being exhausted by water containing 127 p. p. m. as calcium carbonate each of sodium and chloride, 131 p. p. m. as calcium carbonate of calcium and 124 p. p. m. as calcium carbonate of bicarbonate, is found from the following data to have a capacity of 11.7 kilograins as calcium carbonate per cubic foot of cation resin.

A series of cylindrical containers about 16 inches long and about 3 inches in diameter which are made of cardboard lined with metal foil and coated with asphaltum or other waterproofing material are provided with a liquid inlet at the bottom of the container and a liquid outlet at the top of the container. These may consist simply of a. cork through which extends a glass tube onto which is attached rubber tubing.

The containers or cartridges are all packed in an indentical manner with alternate layers of an activated and rinsed granular cation active resin which is a nuclear sulfonated phenol-aldehyde condensation product, and an activated and rinsed anion resin A prepared as described in detail below, said layers being packed suficiently tightly to prevent substantial intermixing of the two types of resin at the interfaces.

In order to determine the initial capacity of the particular combination, a single cartridge is exhausted by water containing 135 p. p. m. as calcium carbonate of sodium and bicarbonate and 129 p. p. m. as calcium carbonate of calcium 4 and chloride. The resin combination is found from the following data to have an initial capacity of 18.1 kilograins as calcium carbonate per cubic foot of cation resin.

Properties of Effluent Specific ui h u 1 mg FMA as No as 00 as ohms ness as pii p. p. m. p. p. m. p. p. m.

22 800, 000 0 0 0 0 ii. 0 35. 1 996, 000 0 0 0 0 0. 3 79. 1 1, 270, 000 0 0 0 0 6. 7 S9. 5 900, 000 0 0 0 0 5. 9 128. 3 800, 000 0 0 0 0 5. 0 145. 1 59, 000 0 0 107 0 4. 7 200 45,000 0 7. 5 133 0 5. 2

The remaining cartridges are exhausted in a similar manner, one at a time, at regular intervals. After 40 weeks the final cartridge, upon being exhausted by water containing 126 p. p. m. as calcium carbonate of sodium, 133 p. p. m. as calcium carbonate of calcium, 131 p. p. m. as calcium carbonate of chloride and 134 p. p. m. as calcium carbonate of bicarbonate, is found from the following data to have a capacity of 13.5

kilograms as calcium carbonate per cubic foot of cation resin.

Properties of Efiiuent Specific ai 035%? H mug B n FM 4 as Na as 00 as ohms 2 11055 as pH 11.1). m. p p. m. p. p. m. p p m The present invention is not limited to the combination of the particular anion and cation resins only in the 1:1 proportion by volume of the example. In general, I prefer mixing the resins in a proportion of 1:1 by volume but I have found that this proportion can be varied from 3:1, cation anion, to 1:3, cation: anion, all proportions being expressed in parts by volume.

Preparation of resin A" 203 parts of tetraethylene pentamine (1.1 mols) 297 parts of epichlorohydrin (3.2 mols) 500 parts of water The tetraethylene pentamine is charged into a suitable reaction vessel provided with an agitator and a means for cooling the vessel. The water is added to the tetraethylene pentamine, the resulting solution is cooled to about 44-47 C., and the epichlorohydrin is added slowly while the reacting mixture is being continuously agitated and kept at a temperature between 44-4'I C. After all the epichlorohydrin has been added the resulting syrup is maintained at a temperature of about 50 C. for about 8 hours.

The gelled syrup is then heated or cured at a temperature of about -105 C. for 17-18 hours. The cured resin is ground and the ground material set aside for use in the resinous mixtures of the present invention.

The present invention is not limited to the particular resins described in the example. Any granular water-insoluble resinous reaction product of an alpha-chloro-beta, gamma-epoxy compound and an alkylene polyamine in the molar amines may be employed.

Examples of suitable polyamines include 1,3- diaminopropane; 1,4-diamino-n-butane, 1,3-diamino-n-butane, 1,5-diamino-n-pentane, 1,6-diamino-n-hexane, 1,10-diamino-n-decane, 1,6-diamino-3 methyl-n-hexane, 3,3'-diamino dipropyl ether, and other similar diamines containing hetero atoms in the chains separating the amino groups, triethylene teiramine, pentaethylene hexamine and all of the higher homologs thereof containing additional CH2CH2NH groups in the chain between the primary amino groups ets. Complex mixtures of polyethylene polyamines of high molecular weight obtained by the addition of large numbers of molecules of ammonia to ethylene dibromide or ethylene dichloride and the like may be used.

It is essential that the molar ratio of epichlorohydrin to the polyamine be at least about 2:1 when the two substances are brought together in order to obtain insoluble resins. There is no maximum amount of epichlorohydrin which may be used but generally it should .not exceed a molar ratio of 5:1 or with polyarnines having more than five amino groups the ratio should not be greater than 1 mol of epichlorohydrin for each amino group in the polyamine.

Instead of epichlorohydrin other substances having an alpha-chloro-beta,gamma-epoxy arrangement are suitable for reaction with polyamines to produce anion active resins. Among these some examples are:

Cl-OH-r- The present invention is not limited to a single particular cation active resin and any nuclear sulfonated phenol-aldehyde condensation product. for example the product of the trade name Amberlite IR-lOO which is manufactured by the Resinous Products Company, or that sold by the Refinite Corporation as Zeolite mm may be used.

The cation active resin may be activated by treatment with dilute acid solutions, e. g., 0.l-10% of hydrochloric acid, sulfuric acid, etc., followed by washing of the material with water to remove free acid.

The anion active material may be activated by treatment with a dilute solution of an alkaline material, e. g., 01-25% solution of sodium hydroxide, sodium carbonate, by corresponding potassium salts, etc.

The resin combination of the present invention may be used in a large household or industrial liquid purification installation or it may be used in a disposable cartridge. In either case the resin combination may take the form of a homogeneous mixture of the two types of resin or it may consist of alternate layers of any desired thickness of anion active resin and cation active resin packed tightly enough to prevent undue mixing of the two types of resin. Thus, my resin combination is one comprising anion active resin and cation active resin in which at least some of the anion active resin particles are in direct contact with at least some of the cation active resin particles. Whenever referred to in the present specification as resin combination," this meaning is intended.

In the present specification and claims appended thereto, the term "shelf life is intended to indicate the stability upon standing (for example, on the shelf of a supplier) of a combination of resins. If, after at least 24 weeks the resin combination has a capacity for the removal of ionizable solids from liquid media of at least 7 kilograins as calcium carbonate per cubic foot of cation resin, then the resin combination is said to have a satisfactory shelf life or a shelf life of at least 24 weeks.

The term ionizable solids" or ionizable materials" is intended to include both volatile and non-volatile materials. The major proportion of these solids are inorganic, but some organic substances may be included. These ionizable solids are impurities in the sense that they are not desired in admixture in the fiuid to be purified but they may in themselves be valuable or desirable materials.

The capacity of the resin combination is calculated in the following manner from the experimental-data given in the examples. It has been found that water having a resistance of 50,000 ohms or higher is generally comparable to distilled water and of satisfactory purity. Accordingly, the measurement of the specific resistance of effluent over a period of time will indicate the point at which the water is no longer of the desired degree of purity, i. e., the point at which the resistance drops below 50,000 ohms. Knowing how much water has fiowed through the resin combination, it is possible to calculate the number of gallons of good water which were prepared before exhausting the resins. The number of gallon of influent, it is possible to determine the 3. A combination of substantially equal propornumber of grains of ionizable solids removed by tions by volume of an anion active granular, the resin combination from the water which water-insoluble, resinous reaction product of passed through. This figure is converted to epichlorohydrin and tetraethylenepentamine in grains per cubic foot of cation resin by multiplythe ratio of 3 mols of epichlorohydrinxper' mol of ing it by 28.3 which is equal to the number of tetraethylenepentamine and acation active granliters in a cubic foot, and dividing by the number ular, water-insoluble, nuclear sulfonated phenolof liters of resin. Division of the figure so obaldehyde condensation product, said combination tained'by 1,000 gives the capacity of the resin after standing for 28 weeks having a capacity for combination in kilograms as calcium carbonate the removal of ionizable solids from aqueous soluper cubic foot of cation resin. This method may tiOn of about 11 kilograins as calcium carbonate be summarized by the following working equaper cubic foot of cation resin. tion: GRACE ROSE STROH.

Capacity (kilograins as GaCO /ft.

. T0166 (gallons of good waterXgrains as CaCQ, of influentxfifi gg This is a continuation-in-part of my copending REFERENCES CITED apphcatlon senal 68817091111 August 61 1946 The following references are of record in the i igfif file of this patent:

l. A combination of an anion active, granular, UNITED STATES PATENTS water-insoluble, resinous reaction product of Number Name Date epichlorohydrin and an alkylene polyamine in the 576,452 Hart Feb. 2, 1897 ratio of at least two mols of epichlorohydrin per 2,204,539 Wassenegger et a1. June 11, 1940 mol of polyamine and a cation active granular, 2,404,367 Durant et al July 23, 1946 water-insoluble, resin which is a nuclear sul- 2,451,272 Blann Oct. 12, 1948 fonated phenol-aldehyde condensation product, 2,461,505 Daniel Feb. 15, 1949 said combination after standing for at least 24 2, 6 3 Dudley e a1 M y 1 1 weeks having a capacity for the removal of ioniz- 2.47 .3 2 Quinn June 28, 1949 able solids from liquid media Of at least 7 kill) OTHER REFERENCES grains as calcium carbonate per cubic foot of cation resin.

2. A combination as in claim 1 which contains the anion and cation active resins in substantially equal proportions by volume.

Ser. No. 359,575, Smit (A. P. C.) published May 11, 1943. r 

1. A COMBINATION OF AN ANION ACTIVE, GRANULAR, WATER-INSOLUBLE, RESINOUS REACTION PRODUCT OF EPICHLOROHYDRIN AND AN ALKYLENE POLYAMINE IN THE RATIO OF AT LEAST TWO MOLS OF EPICHLOROHYDRIN PER MOL OF POLYAMINE AND A CATION ACTIVE GRANULAR, WATER-INSOLUBLE, RESIN WHICH IS A NUCLEAR SULFONATED PHENOL-ALDEHYDE CONDENSATION PRODUCT, SAID COMBINATION AFTER STANDING FOR AT LEAST 24 WEEKS HAVING A CAPACITY FOR THE REMOVAL OF IONIZABLE SOLIDS FROM LIQUID MEDIA OF AT LEAST 7 KILOGRAINS AS CALCIUM CARBONATE PER CUBIC FOOT OF CATION RESIN. 